I read on Microsoft site that Microsoft has taken away the ability to change explorer background in Windows 10 as well as other specific locations.
Seems like the only way to change all Windows colors is to buy WindowBlinds latest 10 version and use their supplied skin studio software to make a special WB theme skin,
or buy Windows Style Builder to make a theme file. From what I've read both these methods have issues along with steep learning curves just to do what could be done so easily in older Windows operating systems. For myself, I don't think it's worth all the trouble to waste money to change a few colors here and there risking incompatibility crashes/bricking of Windows 10.
If anything I would just use the two registry files in my first post. One that adds the blue to most windows, and the reset file to set back to default colors.
EDIT:
Using a different color other than white "Window" can expose flaws/annoyances in Classic Shell start menus.
Depending on how the file text and mask images were structured in the skin file, (example a 7 style .skin7),
the program's tree area and the search box will change color as well.
EDIT:
In most cases, the below text can be added to the skin file at appropriate places to override back to white color:
Programs_background=#FFFFFF
Search_text_background=#FFFFFF